The present invention relates to soy protein, phytoestrogens and dietary fibres and compositions thereof suitable for preventing, alleviating and/or treating pulmonary diseases. The compositions are particularly useful in treating e.g. chronic obstructive pulmonary disease (COPD), inflammation of the airways, asthma, bronchoconstriction, bronchitis, and small airways disease. The present invention also relates to the use of these compositions as a medicament and/or in the manufacture of a medicament for treating a subject suffering from a pulmonary disease, more particularly chronic obstructive pulmonary disease (COPD), inflammation of the airways, asthma, bronchoconstriction, bronchitis, and/or small airways disease. The present invention also concerns use of a composition according to the present invention in the prevention and/or treatment of said diseases and disorders. In addition, the present invention also provides methods for preventing and/or treating and/or prophylactically treating and/or alleviating by therapy said diseases and disorders.
The airways of the human and animal body consist of a series of tubes and passages that include the throat, the larynx and the trachea. In the chest cavity the trachea divides into the right and left bronchi, or bronchial tubes, that enter the lungs. The branches of the bronchi subsequently become more narrow and form tubes, the bronchioles, that divide into even more narrow tubes, the alveolar ducts. The end of each alveolar duct forms a cluster of thinly walled sacs termed the alveoli.
Pulmonary diseases are diseases generally affecting the lungs. The airways and the lungs are subject to many disease causing and/or disease stimulating factors such as e.g. inhaled pathogens like bacteria and viruses, allergens and toxic substances such as cigarette smoke or air pollutants. Such factors generate disorders with symptoms like e.g. difficulty in breathing, chest pains, coughing, and wheezing.
Several terms have been used to describe a group of conditions now generally recognized as leading to a limitation or obstruction of the flow of air in the airways and in the lungs. Obstructive pulmonary disease (OPD) and chronic obstructive pulmonary disease (COPD) are clinical terms describing diseases characterized by an obstruction or limitation of airflow during expiration. For COPD the obstruction or limitation is persistent. The terms represent a clinical rather than a pathological diagnosis and relate to diseases such as e.g. inflammation of the airways, asthma, bronchitis, and small airways diseases. However, the nomenclature in the field of obstructive pulmonary diseases is complex and sometimes confusing in spite of many attempts to define conditions such as asthma and bronchitis.
It is widely recognized that COPD is not a disease entity, but rather a complex of conditions characterized by airflow limitation or obstruction. The limitation or obstruction may be variable over short periods of time and reversible, even though an underlying irreversible trait may persist. Unless treated, the disease is likely to progress and lead to a seriously reduced airflow limitation. This reduction is usually, but not always, persistent and typically shows a more rapid progressive deterioration with age than normal. Clinical studies of acute exacerbations of obstructive pulmonary diseases are difficult because of i) the heterogeneous nature of COPD, ii) diffuse symptoms that can vary spontaneously, and iii) difficulties in defining a clinical response both in the short term and in the long run. Also, the role of e.g. bacterial infections and the subsequent use of antibiotics in connection with pulmonary diseases is controversial, and much evidence shows that although bacterial infections have a significant role in acute exacerbation, the role of said infections in the progression of obstructive pulmonary diseases is less certain.
Accordingly, any of the above-mentioned conditionsxe2x80x94whether transient or chronicxe2x80x94may result in an airflow limitation or obstruction and may therefore be potentially associated with obstructive pulmonary diseases. The conditions may, however, also be present anatomically without generating an impairment of pulmonary function that is sufficient to qualify for the definition OPD or COPD.
An obstruction of the airways is measured by FEV1 as forced expiratory volume in the first second of expiration. Lung function measured as the FEV1 increases into young adulthood and then it starts to decrease. In normal non-smokers, the rate of decline in FEV1 is about 20 ml per year, i.e. about 1 liter over a 50-year period. A much more rapid decline is observed in smokers. On average, the decline is twice that of normal non-smokers. However, in about 15% of all smokers, lung function declines at a rate much more rapid than the decline observed in the average smoker. Consequently, airways diseases are strongly influenced by individual rates of decline in FEV1.
Asthma has traditionally been regarded as a respiratory disease of acute airway obstruction, and research as well as therapeutic attention has focused principally on the mechanisms leading to acute bronchospasm. One of the conventional therapies has consisted of bronchodilators to regulate airway smooth muscle contraction. However, current state of the art asthma therapy does have side effects, mostly due to undesirable effects from the inhalation steroids used.
A wide range of pharmaceuticals have been developed by the pharmaceutical industry and evaluated in clinical trials. Although being capable of inhibiting mast cell-mediated acute allergic bronchoconstriction, none of these pharmaceuticals are suitable for use in a prophylactical treatment or maintenance treatment of asthma. Medicaments such as xcex22 agonists have been introduced in order to treat airways diseases and in particular asthma. xcex22 agonists inhibit the release of histamine into the circulation of asthmatics undergoing an allergen provocation. This pharmacological property may contribute to the well-recognized ability of xcex22 agonists to inhibit allergen-induced bronchoconstriction. However, while xcex22 agonists are exceptional mast cell stabilizing agents, sole therapy with these agents may actually enhance hyperresponsiveness of airways to exogenous stimuli such as inhaled histamine, most likely due to a minimal effect on airway inflammation.
Widespread use of xcex22 agonists have lead to a criticism based on a hypothesis involving the so-called xe2x80x9casthma paradoxxe2x80x9d. According to the hypothesis, xcex22 agonists have undesirable effects on the normal role of mast cell degranulation as an endogenous anti-inflammatory mechanism to prevent antigens from entering the lower airways and limit the extent of the subsequent repair process.
Adlercreutz (Finnish Medical Society, Ann. Med. 29,95-120 (1997)) has reviewed the phytoestrogen classes of lignans and isoflavones and has described their influences on a range of cellular activities and metabolic events. It is stated that despite an abundant literature at this early stage of dietary phytoestrogen research, much work is needed before any recommendation as to phytoestrogen consumption can be made. However, experimental and epidemiological evidence does support the view that these compounds do not have any negative effects and that they may form a group of substances with a great potential in preventive medicine. It is emphasised that at present, no definite recommendations can be made as to the dietary amounts needed for disease prevention. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres. Gooderham (J. Nutr. 126(8), 2000-2006 (1996)) has suggested that although soy protein supplementation to a typical Western diet may increase plasma concentrations of isoflavones, this may not necessarily be sufficient to counter disease risk factors. Increases in serum levels of isoflavones following a soy rich diet were found to be quite variable among analysed subjects. This was thought to be due to e.g. the timing of the soy protein consumption or the composition of the gut flora. The metabolism of isoflavones in the gut is variable among individuals and remains to be elucidated. It is stressed that the isoflavones in human plasma predominantly exist in the inactive glucuronide conjugated form, and only a small amount such as approx. 10 percent exists in the active free and sulphate conjugated forms. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
Hendrich (J. Nutr. 124(9Suppl.), 1789S-1792S (1994)) has reported that isoflavones may be of great potential benefit to human health maintenance and that isoflavones may be health-protective in amounts potentially available from a human diet containing daily soy foods. The food content of isoflavones is in the range of from 0.1 to 1 mg/g in soy foods. Several factors such as variety of soybean, processing and the addition of other ingredients to the food influence isoflavone contents of foods. It is stated that human intestinal bacteria can destroy ingested isoflavones to a great extent and that this may be why only 15 to 20 percent of isoflavones are reported to be recoverable in intact form from the urine and faeces. It is emphasised that much work remains to determine the relation between concentration of isoflavones in human urine and plasma and the biological effects of the isoflavones. It is noted that although more health-related animal data need to be obtained, the time is approaching when long-term human feeding trials of purified isoflavones and foods containing isoflavones to examine health-related outcomes may be warranted. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
Knight (Maturitas 22, 167-175 (1995)) provides a synopsis of the literature relating principally to the clinical effects of phytoestrogens on the diseases associated with ageing. It is concluded that isoflavones represent a large and exciting group of compounds with potential benefits to many diseases. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
Knight (Obstet. Gynecol. 87, 897-904 (1996)) has reviewed the sources, metabolism, potencies, and clinical effects of phytoestrogens on humans. The review suggests that phytoestrogens are among the dietary factors affording protection against heart disease in vegetarians. Based on epidemiologic and cell line studies, it is emphasised that intervention studies are now an appropriate consideration to assess the clinical effects of phytoestrogens because of the potentially important health benefits associated with the consumption of foods containing these compounds. It is concluded that clinical applications for phytoestrogens are still in their infancy. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
Reinli (Nutr. Cancer 26, 123-148 (1996)) has reviewed the literature for quantitative data on the levels of known phytoestrogens (daidzein, genistein, coumestrol, formononetin and biochanin A) in food plants. It is reported that the isoflavones daidzein and genistein may exist in four related chemical structures, i.e. an aglycone structure (daidzein and genistein), a 7O-glucoside structure (daidzin and genistin), a 6xe2x80x2-O-acetylglucoside structure (6xe2x80x2-O-acetyidaidzin and 6xe2x80x2-O-acetylgenistin), and a 6xe2x80x2-O-malonylglucoside structure (6xe2x80x2-O-malonyidaidzin and 6xe2x80x2-O-malonylgenistin). The conjugates (7-O-glucosides, 6xe2x80x2-O-acetylglucosides, and 6xe2x80x2-O-malonylglucosides) are transformed to aglycones, which are sometimes called free isoflavones, through hydrolysis in the intestinal tract by xcex2-glucosidase enzymes of gut bacteria. Acid hydrolysis in the stomach may also contribute to the formation of free isoflavones. It is unclear how readily conjugates undergo intestinal hydrolysis and subsequent absorption. It is stressed that isoflavones are metabolised differently by different animals and humans. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
WO 95/10512 relates to a process for producing an aglucone isoflavone enriched vegetable protein whey and discloses in one embodiment a whey having a dry basis genistein content of about 2.6 to about 8.7 mg/gram and a dry basis daidzein content of about 2.5 to about 6.0 mg/gram. No reference is made to a treatment of a pulmonary disease by using a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
WO 95/10529 relates to a process for producing an aglucone is isoflavone enriched protein concentrate and discloses in one embodiment a concentrate having on a dry basis a genistein content of about 1.0 to about 2.0 mg/gram and a daidzein content of about 0.7 to about 1.5 mg/gram. No reference is made to a treatment of a pulmonary disease by using a composition comprising a combination of soy protein, a high content of a phytoestrogen compound and dietary fibres. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
WO 95/10530 relates to a process for producing an aqueous extract comprising protein and glucone isoflavones and discloses in one embodiment a vegetable protein isolate having a dry basis genistein content of about 1.5 to about 3.5 mg/gram and a dry basis daidzein content of about 1.0 to about 3.0 mg/gram. No reference is made to a treatment of a pulmonary disease by using a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
WO 97/31546 discloses data from total replacement programmes (for 6 weeks) in weight reduction studies conducted at Karolinska Hospital in Sweden. It is shown that products with isolated soy protein and soy cotyledon fibres reduce serum triglyceride levels by a maximum of 44 percent and cholesterol levels by a maximum of 33 percent for a patient population a with mean initial cholesterol content of 6.25 mmol/l. No reference is made to a treatment of a pulmonary disease by using a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
WO 97/37547 discloses an isoflavone-enriched soy protein product having a protein content greater than 60 percent of total dry matter, a total dietary fibre content of less than 4 percent of total dry matter, a sucrose content greater than 10 percent of total dry matter, a total content of sulphur-containing amino acids greater than 2.2 percent of the total amino acid content, a stachyose content of less than 1.5 percent of total dry matter, and a total isoflavone content greater than 2.5 mg/gram, equivalent to 0.25 percent. The use of soy cotyledon fibres is not anticipated and the claimed invention is for use as an ingredient in the production if an edible-product and not in a treatment of pulmonary diseases. Also, the product differs from the present invention by comprising total dietary fibre in an amount of less than 4 percent of total dry matter, by containing an unusually low amount of stachyose and a high amount of sulphur-containing amino acids. No reference is made to a treatment of a pulmonary disease by using a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
U.S. Pat. No. 5,320,949 discloses a process for producing an aglucone isoflavone enriched fibre from a vegetable protein material in the form of a slurry and discloses in one embodiment an aglucone enriched fibre product directly obtainable from said process and having a genistein content of about 1.0 and 2.0 mg/gram and a daidzein content of about 0.7 to 1.7 mg/gram. No reference is made to a treatment of a pulmonary disease by using a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres. No reference is made to a composition comprising soy cotyledon fibres and a phytoestrogen compound.
U.S. Pat. No. 5,352,384 discloses an aglucone enriched fibre product having a genistein content of about 1.0 and 2.0 mg/gram and a daidzein content of about 0.7 to 1.7 mg/gram. No reference is made to a treatment of a pulmonary disease by using a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
EP 827 698 A2 and EP 827 698 A3 disclose a process for producing an aglucone isoflavone enriched extract from a vegetable material containing isoflavone conjugates and protein. No reference is made to a treatment of a pulmonary disease by using a composition comprising a combination of soy protein, a high content of a phytoestrogen compound and dietary fibres. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
An abstract presented at the American Heart Association""s 38th Annual Conference on Cardiovascular Disease Epidemiology and Prevention held in March 1998 disclosed a diet supplemented with 25 grams of soy protein containing 4 mg, 25 mg, 42 mg, and 58 mg of isoflavone, respectively. No reference is made to a treatment of a pulmonary disease by using a composition comprising a combination of soy protein, a high content of a phytoestrogen compound and dietary fibres. No reference is made to a composition comprising a combination of soy protein, a high content of a phytoestrogen compound, and dietary fibres.
The present invention provides a nutritional composition having a fixed, high amount of a phytoestrogen compound such as e.g. naturally occurring isoflavones. More particularly the present invention provides a nutritional composition of soybean extractable ingredients having a high, fixed amount of a phytoestrogen compound such as e.g. naturally occurring isoflavones.
The present invention represents a new approach to treatment of pulmonary diseases and provides a nutritional composition comprising a) soy protein, preferably isolated soy protein, b) a high, fixed content of a plant hormone in the form of a phytoestrogen compound, such as e.g. naturally occurring isoflavones, and c) dietary fibres, preferably soybean fibres, more preferably soybean fibres manufactured from the cotyledon of soybeans hereinafter referred to as soy cotyledon fibres.
The present invention is useful in the prevention and/or effective treatment of pulmonary diseases such as e.g. airway inflammation, asthma, bronchitis and small airways diseases, in particular asthma including chronic asthma such as e.g. asthma characterised by a chronic inflammatory condition. The present invention is believed to be capable of increasing FEV1 of a subject, measured by forced expiratory volume in the first second of expiration, as well as being capable of treating, alleviating and/or eliminating in particular i) inflammation of the airways, ii) mucus hypersecretion, and iii) bronchoconstriction. A composition according to the present invention may be comprised in a micronutrient as defined herein below.
Phytoestrogen compounds are naturally occurring plant hormones showing a structural similarity to 17xcex2-estradiol. Phytoestrogens consist of a number of classes including isoflavones, coumestans, lignans and resorcylic acid lactones. The class of isoflavones consists of among others genistein, daidzein, equol, glycitein, biochanin A, formononetin, and O-desmethylangolesin. The isoflavones genistein and daidzein are found almost uniquely in soybeans. When present in the plant the isoflavones are mainly in a glucoside form, i.e. attached to a sugar molecule. Isoflavones in this glucoside form can be deconjugated to yield isoflavones in a so-called aglycone form, which is the biologically more active form of isoflavones and which is absorbed faster and to a greater extent in the human gut than isoflavones in the glucoside form. In vitro studies have examined the relative estrogenic effect exerted by various phytoestrogens including isoflavones. The resulting potencies as compared to estradiol (having a relative potency of 100), have been reported by Knight (Maturitas 22, 167-175 (1995)) for among others genistein (0.084) and daidzein (0.013). However, the results also showed that the estrogen receptor complexes formed by estradiol and isoflavones such as genistein and daidzein are functionally equivalent. The comparative dissociation constant of genistein for the estrogen receptor, as determined in competitive binding assays, was found to be from 100 to 10.000 times higher than that of estradiol.
The term xe2x80x9cnaturally occurringxe2x80x9d substance as used in the present specification and the appended claims refers to a substance originally isolated from a natural source, such as an animal or a plant, for example a soy plant, or modified forms of such a sub-stance. The naturally occurring substance for use in a composition according to the present invention may be included in the composition as part of the natural source or in any type of extract, isolate or the like thereof, or it may have been isolated from a plant source or synthesized biologically, microbiologically, or chemically or by any other means.
Accordingly, in one aspect the present invention provides a composition comprising
(a) a soy protein source, selected from isolated soy protein, soy protein concentrate, or soy flour, said soy protein source providing an amount of soy protein, which is at least 45 weight percent of the total protein content of the composition, said total protein content providing at least 15 percent of the total energy content of the composition,
(b) at least one phytoestrogen compound in an amount of more than 0.10 weight percent of the soy protein content of the composition, and
(c) dietary fibres in an amount of more than 4 weight percent of the total weight of the composition on a dry basis.
In a more preferred aspect the present invention provides a composition comprising
(a) isolated soy protein in an amount of at least 50 weight percent of the total protein content of the composition, said total protein content providing at least 15 percent of the total energy content of the composition,
(b) at least one phytoestrogen compound in an amount of more than 0.10 weight percent of the soy protein content of the composition, and
(c) soybean fibres in an amount of more than 4 weight percent of the total weight of the composition on a dry basis.
In a most preferred aspect the present invention provides a composition comprising
(a) isolated soy protein in an amount of at least 50 weight percent of the total protein content of the composition, said total protein content providing at least 15 percent of the total energy content of the composition,
(b) at least one phytoestrogen compound in an amount of more th an 0.10 weight percent of the soy protein content of the composition, and
(c) soy cotyledon fibres in an amount of more than 4 weight percent of the total weight of the composition on a dry basis.
Phytoestrogen compounds according to the present invention are defined as naturally occurring plant substances, said substances being either structurally or functionally similar to 17xcex2-testradiol or generating estrogenic effects. Phytoestrogens consist of a number of classes including isoflavones, coumestans, lignans and resorcylic acid lactones. Examples of isoflavones according to the present invention are genistein, daidzein, equol, glycitein, biochanin A, formononetin, and O-desmethylangolesin. The phytoestrogen compounds of a composition according to the present invention are preferably isoflavones, more preferably genistein, daidzein, glycitein and/or equol yet more preferably genistein, and/or daidzein and even more preferably genistein. Genistein and daidzein are found almost uniquely in soybeans. A preferred composition according to the present invention may accordingly comprise a single isoflavone, such as genistein, daidzein, glycitein or equol, or it may comprise at least one isoflavone selected from the group consisting of at least genistein, daidzein, glycitein and equol.
In one embodiment the present invention provides a composition according to the present invention for use as a medicament. The use of a composition according to the present invention in the manufacture of a medicament for treating a subject suffering from pulmonary diseases represents another embodiment of the present invention. Such a medicament may be effective in preventing and/or treating a pulmonary disease such as e.g. a disease selected from the group consisting of inflammation of the airways, bronchoconstriction, bronchitis, asthma, and small airways diseases.
The present invention also provides a method of preventing, alleviating and/or treating by therapy a pulmonary disease in a human or animal body, said method comprising administration of a composition according to the present invention in an amount effective in treating, alleviating and/or preventing inflammation of the airways and/or bronchoconstriction and/or bronchitis and/or asthma and/or small airways diseases.
According to another embodiment the present invention provides a method of preventing, alleviating and/or treating by therapy a pulmonary disease in a human or animal body, said method comprising administration of a composition according to the present invention in an amount effective in reducing and/or eliminating mucus hypersecretion and/or dyspnea of a subject and/or increasing FEV1 as measured by forced expiratory volume in the first second of expiration.
Obstructive pulmonary disease (OPD) including chronic obstructive pulmonary disease (COPD) as used herein is:defined as a condition comprising subjects with airways limitations or obstructions or subjects with a mucus hypersecretory condition including chronic mucus hypersecretion, i.e. subjects with asthma including chronic asthma and subjects with bronchitis including chronic bronchitis. However, a clear distinction between e.g. bronchial asthma and chronic bronchitis can be difficult and sometimes impossible to make, and a sharp distinction between COPD and OPD is therefore not always possible.
Mucus hypersecretion and a limited or obstructed airflow are two major characteristics of COPD. According to one presently preferred theory, mucus hypersecretion is an initial mechanism that leads to recurrent respiratory infections, that in turn generates a destruction of the airways"" and promotes a development of pulmonary parenchyma and airflow obstruction. At least two separate conditions, i) mucus hypersecretion and ii) dyspnea, are identifiable due to an obstructive or limited lung function. Chronic mucus hypersecretion and obstructive airflow are not necessarily related, since an individual may have a hypersecretory disorder only, or an obstructive disorder only, or both a hypersecretory and an obstructive disorder. Chronic mucus hypersecretion is associated with an impaired mucociliary clearance and may therefore predispose to lung cancer by causing a prolonged contact between potential carcinogens with the bronchial epithelium. Accordingly, a composition according to the present invention may be effective in treating and/or alleviating mucus hypersecretion and dyspnea in a subject.
Asthma as used herein is:defined as a respiratory disease in which spasm and constriction of the bronchial passages and swelling of their mucous lining cause obstruction of breathing, often, but not exclusively, due to allergy. One mechanism for expiratory airflow limitation in asthma is a smooth muscle contraction leading to a narrowing of the airway lumen. Asthma is frequently divided clinically into extrinsic and intrinsic asthma, separating asthma triggered by environmental allergens from that in which atopy does not appear to play a major role. Consequently, a composition according to the present invention may be effective in preventing, treating and/or alleviating smooth muscle contraction.
In asthma the airways are occluded by tenacious plugs of exudate and mucus, and there occurs a fragility of airway surface epithelium, thickening of the reticular layer beneath the epithelial basal lamina, bronchial vessel congestion and edema. An increased inflammatory infiltrate comprising xe2x80x9cactivatedxe2x80x9d lymphocytes and eosinophils, and an enlargement of bronchial smooth muscle, particularly in medium-sized bronchi, is also observed. Asthma comprises at least extrinsic (atopic or allergic) and intrinsic (non-atopic) divisions, each of which present clinically in a variety of ways. A composition according to the present invention may be effective in preventing and/or alleviating the formation of tenacious plugs of exudate and mucus, effective in preventing, alleviating or treating a fragility of airway surface epithelium subsequently generated by mucus secretion, effective in preventing, reducing or eliminating any thickening of the reticular layer beneath the epithelial basal lamina, and effective in preventing, alleviating or treating bronchial vessel congestion and/or edema.
Asthma may in some cases be regarded as a chronic inflammatory disease. Since the term chronic asthmatic bronchitis has no clearly defined pathologic equivalent, patients having a chronic productive cough normally associated with chronic bronchitis, as well as bronchospasms, at the same time as having an airflow obstruction, will be regarded as suffering from both chronic bronchitis as well as small airways disease (chronic obstructive bronchitis) and asthma, since the pathology presumably would be that of those conditions.
A composition according to the present invention may be effective in preventing, alleviating and/or curing inflammation of the airways, whether transient or chronic. Airway inflammation is thought to be an important contributor to asthma, and airway inflammation may well be present even in the absence of severe symptoms of asthma. In one particularly preferred aspect the present invention provides a treatment and/or alleviation of an inflammation of the airways by means of an anti-oxidative effect exerted by a composition according to the present invention. The anti-oxidative effect is exerted in particular by naturally occurring isoflavones forming part of a composition according to the present invention.
A composition according to the present invention may be effective in increasing FEV1, as measured by forced expiratory volume in the first second of expiration, said effect being exerted by the binding of a component of the composition, particularly a naturally occurring isoflavone, to a beta-2-receptor or a receptor belonging to the class of beta-2-receptors. Beta-2-receptors are present on many different types of cells including cells in airways and vessels. A composition according to the present invention may also be effective in generating a dilatation of the airways in a subject, preferably a subject suffering from a pulmonary disease.
The occurrence of bronchial inflammation in asthma is, according to one presently preferred hypothesis, thought to arise at least in part from an airway response to an antigen in an allergic subject. The response includes immediate pulmonary mast-cell activation and initiation of an inflammatory response that develops over hours and is important in the later and more persistent development of bronchial obstruction. A composition according to the present invention may be effective in treating, alleviating and/or eliminating several of the causes of airway obstruction thatxe2x80x94alone or in combinationxe2x80x94contributes to bronchial hyperresponsiveness, i.e. the fundamental defect in asthma. Importantly, airway inflammation is believed to be a crucial component for i) the chronicity of asthma, ii) the intensity of airways hyperresponsiveness, and iii) the absence of a complete therapeutic control, when bronchodilator therapy is used alone. Consequently, a composition according to the present invention may be effective in controlling, reducing and/or eliminating edema, mucus secretion, and inflammation of the airways resulting at least in part from a response to an allergen.
Although the precise pathogenesis of asthma has yet to be discovered, allergic reactions and respiratory infections are particularly important. Both are frequent factors in asthma and exacerbations of asthma, and both not only trigger acute asthmatic symptoms but may also enhance the degree of airway hyperresponsiveness long after the initial stimulus has been removed. Of particular interest has been the airway""s response to an inhaled antigen. Almost all subjects with allergic asthma experience immediate bronchospasm following inhalation of an antigen, i.e. acute airway obstruction, within 15 min of antigen exposure. In these subjects, antigen inhalation initiates not only immediate bronchocontraction, but also the reappearance of airway obstruction 4 to 6 hours later, a condition known as late asthmatic reaction or LAR. The late asthmatic response has a number of features that are characteristic of chronic asthma such as e.g. less responsiveness to bronchodilator therapy than the isolated acute event, an increased airway responsiveness, and the development of bronchial inflammation. Two features of the LAR to antigen inhalation suggest a linkage to the pathogenesis of asthma: The presence of bronchial inflammation and the enhancement of bronchial responsiveness. Consequently, a composition according to the present invention may be capable of preventing both immediate bronchocontraction as well as a late asthmatic reaction.
Asthmatic reactions following inhalation of an antigen include an immediate release from pulmonary mast cells of preformed mediators and a generation of a variety of factors needed to initiate an acute allergic airway reaction. Because the airways of patients with asthma are hyperresponsive, the immediate bronchial reaction to mast cell bronchospastic mediators is accentuated beyond the pharmacological properties of these substances. With cellular activation by antigen and membrane-bound IgE interaction, the mast cell initiates a generation of leukotrienes and prostaglandins. The leukotrienes, C4, D4, E4, along with histamine, are undoubtedly involved in the acute bronchospastic response because of their airway smooth muscle contractile properties. The generation and release by mast cells of chemotaxic factors is important for the recruitment of inflammatory cells to the airway and for the subsequent development of the late asthmatic response. Accordingly, a composition according to the present invention may be capable of effectively reducing or eliminating mast cell mediated secretion of mediators such as e.g. heparin, histamine and sulphidopeptide leukotrienes C4, D4, and E4.
Associated with the development of the LAR is a recruitment of inflammatory cells to the airway, including neutrophils, macrophages, lymphocytes, eosineophils, monocytes, and basophils. With their entry into the airways, and presumable cellular activation, airway obstruction reappears. It is thought that components of airway obstruction in LAR include bronchospasm, edema, and inflammation. An additional consequence of the LAR is an increase in airway hyperresponsiveness; thus, the asthmatic process is further perpetuated and positively reinforced. Consequently, a composition according to the present invention may be capable of effectively controlling in a late asthmatic response the symptoms of bronchospasm, edema, and inflammation, and in addition also effectively controlling such as reducing and/or eliminating any increase in airway hyperresponsiveness.
Furthermore, mast cells may according to another presently preferred hypothesis produce various cytokines, interleukin 3 (IL-3), interleukin 5 (IL-5), and granulocyte/macrophage colony-stimulating factor (GM-CSF), which can perpetuate the allergic reaction by further priming inflammatory cells. Consequently, a composition according to the present invention may be capable of effectively controlling i.e. reducing and/or eliminating the production of various cytokines, interleukins such as e.g. interleukin 3 (IL-3) and interleukin 5 (IL-5), and granulocyteimacrophage colony-stimulating factor (GM-CSF), and reduce any further priming of inflammatory cells during an early and/or late asthmatic response.
A class of cells termed neutrophils can be found in lavage fluid from an asthmatic subject, but the precise role of neotrophils in the generation of a late allergic reaction has not yet been established. The neutrophil cell has a potential for generating inflammation by releasing e.g. lysosomal enzymes, oxygen metabolites, leukotriene B4 and by synthesising histamine-releasing factor (HRF). HRF can amplify the allergic reaction by causing mediator release from a class of cells termed basophils that also appear during a late allergic reaction. Consequently, a composition according to the present invention may be capable of effectively controlling i.e. reducing and/or eliminating a neutrophil production of e.g. lysosomal enzymes, oxygen metabolites, leukotriene B4 and histamine-releasing factor (HRF).
Evidence also exists for an implication of the group of cells termed eosinophils in an asthmatic response. Circulation of eosinophils leads to an increased severity of airway obstruction. Eosinophil granular associated proteins, including major basic protein (MBP), eosinophil cationic protein, eosinophil-derived neurotoxin, and eosinophil peroxidase are known to have profound effects on airway and cell function. MBP in particular has a number of unique properties accentuating the asthmatic response. MBP can directly injure airway epithelium, promote bronchial responsiveness, and mediate smooth muscle contraction. MBP further activates the release of mediators from mast cells and basophiis. Eosinophils may also be involved in initiating tissue damage associated with various allergic diseases, such as e.g. the epithelial desquamation observed in asthmatics. This tissue damage has been suggested to be mediated in part via the release of cytotoxic mediators such as major basic protein (MBP), eosinophil cationic protein (ECP), and eosinophil peroxidase (EPO).
Eosinophil activation result""s in the release of a number of important mediators, including leukotriene C4, which can contract airway smooth muscle, and platelet-activating factor (PAF). The release process of PAF has not been fully defined, but if secreted, this lipid mediator could contract airway smooth muscle as well as increase bronchial responsiveness. Furthermore, PAF is a potent eosinophil chemoattractant and a functional primer. Accordingly, eosinophils possess properties directly and indirectly causing airway obstruction and promoting bronchial hyperresponsiveness. Consequently, a composition according to the present invention may be capable of effectively controlling i.e. reducing and/or eliminating any increase in the formation of eosinophils during an asthmatic response. A composition according to the present invention may further be effective in controlling the production of eosinophil granular associated proteins including major basic protein (MBP), eosinophil cationic protein, eosinophil-derived neurotoxin, and eosinophil peroxidase. In an even further embodiment, a composition according to the present invention may be effective in controlling i.e. reducing and/or eliminating the release of mediators from mast cells, neutrophils, basophils and eosinophils, in particular the release of mediators such as e.g. leukotriene C4 and platelet-activating factor (PAF), IL-3, GM-CSF and IL-5.
To generate airway inflammation after eosinophil recruitment, a number of events need to occur such as e.g. eosinophil migration to the lung and eosinophil activation. The last event is likely to involve eosinophil adhesion to endothelium and, eventually, airway epithelium. Accordingly, a composition according to the present invention may be effective in preventing eosinophil participation in the bronchial responsiveness process by inhibiting eosinophil adhesion to endothelium and epithelium.
Mast cells may also release compounds such as heparin and related proteoglycans, but the release of such mediators have so far not received much attention from allergy researchers. These highly anionic molecules are normally only associated with the binding histamine within mast cell granules. These molecules may act as natural antiinflammatory molecules and, thus, have a far greater role in the pathogenesis of allergic diseases. Accordingly, a composition according to the present invention may be effective in promoting the release of potentially antiinflammatory molecules such as e.g. heparin and related proteoglycans. Also, it has been reported that another cationic protein, platelet factor 4 (PF4), is a chemotaxic agent for human eosinophils and is a molecule well recognized for its ability to bind heparin. It is therefore plausible that endogenous heparin could be released to limit both the extent of eosinophil recruitment into sites of allergic inflammation as well as the extent of tissue damage induced by cationic proteins. Lymphocytes are also likely to be involved in the pathogenesis of allergic asthma. Recent studies have suggested that heparin acts as an immunomodulator inhibiting lymphocyte activation and trafficking and, like glucocorticosteroids, can also inhibit delayed hypersensitivity responses.
Further evidence of asthma being a chronic inflammatory disease is provided by the observation that an exposure to an allergen that results in tissue damage is likely to lead to a repair of the damage. Evidence of this repair process can most likely be seen in the asthmatic lung, where a thickened basement membrane is believed to be related to subepithelial fibrosis, the presence of myofibroblasts, and collagen deposition. Also, asthma is further characterized by a thickened smooth muscle layer.
The above-mentioned changes appear very early in the disease and are not constricted to patients with chronic asthma. Furthermore, even following chronic treatment with inhaled glucocorticosteroids for periods of up 10 years, the thickness of the basement membrane is not reduced, although such therapy reduces the number of inflammatory cells present in the biopsies and the extent of the epithelial damage. Such clinical observations suggest that once these anatomic changes have appeared they may not be readily reversible, even with the most aggressive therapy currently available. Thus, it is plausible that once established, such anatomic changes may underlie the irreversible component of the disease, and by altering the geometry of the airway wall, these changes may contribute to the persistent airways hyperresponsiveness that does not respond to treatment. Accordingly, a composition according to the present invention may, in one particularly preferred embodiment, be capable of effectively preventing and/or alleviating the formation of a thickened basement membrane or a smooth muscle layer, subepithelial fibrosis, the presence of myofibroblasts, and a deposition of collagen.
Bronchitis as used herein is defined as an acute or chronic inflammation of any part of the bronchi and bronchial tubes. The bronchi are large delicate tubes in the lungs that are attached to the trachea and carry air to smaller tubes in the lungs. In bronchitis, including chronic bronchitis, there is mucous hypersecretion, an enlargement of tracheobronchial submucosal glands, and a disproportionate increase of mucous acini. Acute bronchitis is often characterized by fever, chest pain, severe coughing, and secretion of mucous material coughed up from the respiratory tract. Acute bronchitis affects the branches of the bronchi and may develop into bronchial or lobular pneumonia. Chronic bronchitis may result from repeated attacks of acute bronchitis. Consequently, a composition according to the present invention may be effective in controlling mucous hypersecretion, preventing, alleviating or treating an enlargement of tracheobronchial submucosal glands, and reduce and/or eliminate a disproportionate increase of mucous acini. The pathologic equivalent to chronic bronchitis is a non-specific series of changes in the bronchial wall generally characterized by an increase in the size and number of mucous glands and an increased number of goblet cells in the epithelium. When progressing into a chronic condition, bronchitis is a serious and incurable disorder. Consequently, a composition according to the present invention may be effective in controlling a series of changes in the bronchial wall generally characterized by an increase in the size and number of mucous glands and an increase in the number of goblet cells. A composition according to the present invention may also be capable of reducing and/or eliminating any mucos production including an increased mucos production.
Bronchial infections usually remain confined to the mucosa, and some resolve spontaneously without the need for treatment. Chronic bronchitis affects both the large and small airways. In the large airways, hypertrophy and hyperplasia of glandular structures and goblet cell metaplasia are prominent features of the condition. In the small airways, peribronchiolar fibrosis and airway narrowing may be prominent features. In chronic bronchitis hypertrophy of glandular structures and goblet cell metaplasia in the proximal airways likely contribute to an increased mucus production, the expectoration of which is one defining characteristic of chronic bronchitis. Consequently, a composition according to the present invention may be effective in preventing an airflow limitation in a subject prone to contracting bronchitis and/or to alleviate any airflow limitation or obstruction already present in said subject. Particularly, a composition according to the present invention may be effective in controlling hypertrophy and hyperplasia of glandular structures and goblet cell metaplasia, as well as peribronchiolar fibrosis and a narrowing of the small airways.
Bronchitis may be caused by a number of factors including viral and/or bacterial infection, environmental pollutants including cigarette smoke, and allergy. These factors may occur together or separately. A viral infection may e.g. predispose an individual to a subsequent bacterial infection. Bronchial infections occur in patients with abnormal airways who have reduced host defences. The three major bacterial pathogens isolated during bronchial infections are non-typable Haemophlus influenzae, moraxella catarrhalis, and Streptococcus pneumoniae. A composition according to the present invention may especially be effective in preventing viral and/or bacterial infection in a subject by e.g. increasing the host defences of said subject.
The term small airways as used herein is defined as small bronchi and bronchioles that contain no cartilage, glands or alveoli in their walls and measure 2 mm or less in internal diameter. The term small airways disease is used for a group of non-specific histological changes of peripheral airways found in individuals with a limited or obstructed airflow, including individuals having features such as mucus plugging, chronic inflammation, and muscular enlargement of small airway walls. Small airways disease is present in some patients with the clinical picture of chronic bronchitis. Consequently, a composition according to the present invention may be effective in treating, including prophylactically treating, alleviating and/or preventing a limited or obstructed flow of air through the small airways.
In small or peripheral airways disease, there is inflammation of bronchioli and mucous metaplasia and hyperplasia, increased intraluminal mucus and increased wall muscle. Consequently, a composition according to the present invention may be effective in controlling inflammation of the bronchioli and mucous metaplasia and hyperplasia, and effective in reducing and/or eliminating any increased intraluminal mucus formation and/or any increased wall muscle development.